Make chrome.fileManagerPrivate.getSizeStat return actual available space for Downloads.

chrome/browser/chromeos/extensions/file_manager/private_api_file_system.h

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 //
 // This file provides file system related API functions.
 
 #ifndef CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_FILE_SYSTEM_H_
 #define CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_FILE_SYSTEM_H_
 
 #include <stddef.h>
@@ skipping 137 matching lines @@
   DECLARE_EXTENSION_FUNCTION("fileManagerPrivate.getSizeStats",
                              FILEMANAGERPRIVATE_GETSIZESTATS)
 
  protected:
   ~FileManagerPrivateGetSizeStatsFunction() override {}
 
   // AsyncExtensionFunction overrides.
   bool RunAsync() override;
 
  private:
-  void OnGetLocalSpace(uint64_t* total_size,
-                       uint64_t* remaining_size,
-                       bool is_download);
-
   void OnGetDriveAvailableSpace(drive::FileError error,
                                 int64_t bytes_total,
                                 int64_t bytes_used);
 
   void OnGetMtpAvailableSpace(const MtpStorageInfo& mtp_storage_info,
                               const bool error);
 
   void OnGetSizeStats(const uint64_t* total_size,
                       const uint64_t* remaining_size);
 };
@@ skipping 164 matching lines @@
   // Called when setting a tag is completed with either a success or an error.
   void OnSetEntryPropertyCompleted(drive::FileError result);
 
   ExtensionFunction::ResponseAction Run() override;
   DISALLOW_COPY_AND_ASSIGN(FileManagerPrivateInternalSetEntryTagFunction);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_CHROMEOS_EXTENSIONS_FILE_MANAGER_PRIVATE_API_FILE_SYSTEM_H_